As is well documented, mobile ion contamination can limit die yields during semiconductor processing. In the clean room environment, the scope of mobile ions (particularly sodium ions), incorporated during semiconductor processing can come from moisture, water rinsing, plasma processing and excess exposure to air, etc. Sodium ions in particular are generated very easily and can play an active role in causing contamination when introduced at very low temperatures.
The text book "Instabilities In Silicon Devices," (Elsevier Science Publishers B. V. (North-Holland), 1986 has a chapter devoted to mobile ion contamination. Chapter 8, pp. 403-439, entitled "Mobile Ions in SiO.sub.2 Layers On Si" provides a thorough teaching on mobile ions contamination, which is hereby incorporated by reference.
Mobile ion contamination is very prevalent in today's semiconductor processing. The semiconductor fabrication industry would benefit greatly from a method to cure mobile ion contamination during processing and such a cure is set forth by the methods of the present invention.